You are working as an apprentice for the bksb Newcastle Arena. An indoor sport exhibition is coming to the arena. Your supervisor has asked you to help set up a handball pitch and seating area as shown in the plan view below..

19

Step-by-step explanation:

We know there are 25 boys, meaning if we divide it by 5 we can figure out that the number of girls is 15.

25 - 16 = 9 boys went sailing

15/3 <-- To find out how many of the girls went sailing

dividing it by 3 would also us to have one third going climbing at the remaining 2/3 going sailing

10 girls went sailing

10 + 9

=19